The present invention relates to roofing insulation used in single ply roofing membrane systems, and, in particular, to roofing insulation boards coated on a major surface with a latex containing coating to improve the adherence of single ply roofing membranes to the roofing insulation boards.
Single ply roofing membrane systems are commonly used as roofing systems for low sloping roofs, especially in industrial and commercial applications. Typically, these single ply roofing membrane systems include roofing insulation boards, such as but not limited to perlite insulation boards, wood fiber insulation boards, glass fiber insulation boards, polymer foam insulation boards, and composite insulation boards made up of two or more layers of different materials, such as perlite based, wood fiber based, glass fiber based and polymer foam board layers. These roofing insulation boards are secured to the roof deck by mechanical fasteners or other conventional means. Of the above listed roofing insulation boards, perlite roofing insulation boards, such as perlite insulation boards sold by Johns Manville International, Inc., under the trademark FESCO(copyright), have several advantages over the other types of roofing insulation boards. For example, these perlite roofing insulation boards are typically lower in density and absorb less water than wood fiber roofing insulation boards and, the high inorganic content of the perlite roofing boards, renders the perlite roofing insulation boards much less flammable than the typical wood fiber roofing insulation boards.
A single ply roofing membrane, such as but not limited to membranes made of ethylene propylene diene terpolymer rubber (EPDM), ethylene propylene rubber (EPR), and alloys of ethylene propylene diene terpolymer rubber (EPDM) or ethylene propylene rubber (EPR) with polypropylene (thermoplastic olefin elastomers or TPO""s) or poly(vinyl chloride), overlay and are secured to the upper major surfaces of the roofing insulation boards by conventional mechanical fasteners or with commercially available roofing contact adhesives. These single ply roofing membranes may or may not include reinforcing meshes or scrims located intermediate layers of the material forming the single ply roofing membrane.
The present invention relates to roofing insulation boards having upper major surfaces which are coated with a latex containing coating to improve the bond between the overlaying single ply roofing membrane and the roofing insulation boards when the overlaying single ply roofing membranes are adhesively bonded to the roofing insulation boards and to roofing systems incorporating such coated roofing insulation boards. To improve the bond between the upper major surface of the insulation board and the single ply roofing membrane, the upper major surface of the insulation board is coated with a coating including, by dry weight, between 48.3% and 96% filler, between 3.1% and 33.3% latex; and 0% to 34% sodium silicate.